A new regioselective synthesis of 5- and 6-aryluracil bases based on direct C–H arylations of diverse 1,3-protected uracils has been developed. Benzyl-protected uracils were selected as the most practical in terms of stability during the arylation and facile cleavage of the benzyl groups. Pd-catalyzed C–H arylations in the absence of CuI gave preferentially 5-aryl-, whereas the reactions in the presence
There are disclosed a process for producing a coupling compound of formula (1):
(Y—)
(n-1)
R
1
—R
2
—(R
1
)
(n′-1)
(1),
wherein R
1
and R
2
independently represent
a substituted or unsubstituted aryl group,
which process is characterized by reacting
an unsaturated organic compound of formula (2):
n
′(R
1
X
1
n
) (2)
wherein n, n′, and R
1
are the same as defined above, and
X
1
is the same or different and independently represents a leaving group and bonded with a sp2 carbon atom of R
1
group,
with a boron compound of formula (3):
m
{R
2
(BX
2
2
)
n′
} (3)
wherein R
2
and n′ are the same as defined above,
X
2
represents a hydroxy group, an alkoxy group, in the presence of a catalyst containing
(A) a nickel compound, and
(B) a nitrogen-containing cyclic compound, and the catalyst.
Abstract A convenient one‐step synthesis of 5‐aryl uracils has been developed. The procedure involves heating ethyl 3‐hydroxy‐2‐arylpropenate with urea at 130°C, followed by base‐catalyzed cyclization. The method is simple and high yielding.
Cross-Coupling catalyst comprising a cyclic nitrogen ligand and process using the same
申请人:Sumitomo Chemical Company, Limited
公开号:EP1306131A2
公开(公告)日:2003-05-02
There are disclosed a process for producing a coupling compound of formula (1):
(Y-)(n-1)R1-R2-(R1)(n'-1) (1),
wherein R1 and R2 independently represent
a substituted or unsubstituted aryl group,
which process is characterized by reacting
an unsaturated organic compound of formula (2):
n'(R1X1 n) (2)
wherein n, n', and R1 are the same as defined above, and X1 is the same or different and independently represents a leaving group and bonded with a sp2 carbon atom of R1 group,
with a boron compound of formula (3):
m R2(BX2 2)n'} (3)
wherein R2 and n' are the same as defined above, X2 represents a hydroxy group, an alkoxy group, in the presence of a catalyst containing
(A)a nickel compound, and
(B)a nitrogen-containing cyclic compound, and the catalyst.